Thunderbolt

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jackdaw
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Joined: 16 Feb 2018, 20:30
Location: Wet and Windy North Wales

Thunderbolt

Post by jackdaw » 24 Oct 2019, 20:40

Any one built a Bill Morley 'Thunderbolt'? Got any tips or links to builds etc?
TIA

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F2B
Posts: 142
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Location: 20 m NE of Amsterdam

Re: Thunderbolt

Post by F2B » 24 Oct 2019, 21:41

This must be a vintage design as I can't recall ever having seen one or the plan.

Bruno
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Tobe
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Location: Varberg or Stockholm, Sweden

Re: Thunderbolt

Post by Tobe » 25 Oct 2019, 06:34


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F2B
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Re: Thunderbolt

Post by F2B » 25 Oct 2019, 21:43

jackdaw wrote:
24 Oct 2019, 20:40
Any one built a Bill Morley 'Thunderbolt'? Got any tips or links to builds etc?
TIA
It all depends on what you're expecting from it.
It will prove a handful if you'd be trying the current F2B schedule with the model per plan.
The stab moment arm is -regarding todays standards- very short. For todays standard, look at my avatar >
This results in a lively, rather unstable model.
Therefore, the first thing I would change is using a 4" bellcrank instead of a 3".
This makes the model's behavior a lot 'calmer'.
Use 4 1/2 - 5" handle spacing and the CG at or up to 1/2 " in front of the mainspar.
With that secured, plus the addition of adjustable lead outs and a tip weight box (indispensible trimming aids) I can see this turning into a lovely flying, vintage model.

Reading the description brought a smile to my face.
I mentioned the model being considered 'big'.
Mine is a relatively small one at only 57" span and 62 oz. :mrgreen:

The first 'real' CL aerobatic model I saw was my mentor Paul Tupker's Palmer Thunderbird II Fox .35, 60 ft Laystrate....
LB in Utrecht.jpg
F2B or not to be....

jackdaw
Posts: 150
Joined: 16 Feb 2018, 20:30
Location: Wet and Windy North Wales

Re: Thunderbolt

Post by jackdaw » 25 Oct 2019, 22:43

Thanks for the advice. Both new, both plain bearing, Enya 35 or OS 40FP(ABN)? 60FT - 65FT lines? Just for sport flying.

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F2B
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Re: Thunderbolt

Post by F2B » 15 Dec 2019, 10:28

Ooh, apologies for leaving the topic unanswered :oops:
Yes 60-65 ft. would be fine.
My advice would be using Staystrate from PAW: https://www.eifflaender.com/spares
For .35 - .40 I'd take .35mm cable, .38 is for .60 or equivalent.
Nice feature of Staystrate and it's predecessor Laystrate is that it can be soldered with soft solder.
Never ever however, solder the cable, making a stiff/flexible spot as it will break there.
Not a matter if, only when.
If interested, I'll try digging up the series of pictures I made for constructing proper eyelets, that are soldered, without affecting the cable attached.
Never ever broke one like that since 1970....
F2B or not to be....

jackdaw
Posts: 150
Joined: 16 Feb 2018, 20:30
Location: Wet and Windy North Wales

Re: Thunderbolt

Post by jackdaw » 15 Dec 2019, 12:01

Bought a selection of control wire/cranks/fittings etc to add to that I already had(never done CL so don't remember how I came by them). It's lead out wires I'm a bit short of info on. Bought 1/16" copper tube, which is a good fit in the bellcrank holes, to pass wire through. But should I not use something more substantial for the lead outs from bellcrank to wing tip other than the same wire as the flying wire? I was thinking of lengths of piano wire.
Update on engine after checking my inventory. I've also got PAW 35 plain and PAW 35 BR. Also available in glow is a 48 and 52. All engines are RC but can easily lock carb open.
Decided to start with a Belair profile SU 26 http://www.belairkits.com/detail.asp?id=1200 instead of the full fuselage Thunderbolt. Get the building board populated after Christmas.
As I've said above its the lead out wires and the flying wire connection/disconnection point I'm a bit short of info on.

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F2B
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Re: Thunderbolt

Post by F2B » 15 Dec 2019, 21:33

Take the PAW 35 BR.
If the other engines are RC ones, forget about these. They will 'run away' and unable to keep a steady 2/4 stroke run.

I'll come back on the eyelets on your cables (did I mention Staystrate? No, I'm not a share holder :lol: )
Not the cheapest, yet the best available. Because of the tinning bath thy accept (soft) soldering.
Don't solder the cable, however. I'll come back on 'how to' when you've reached that stage.

For lead out cables up to .46 I'd use 1 mm (~ .40) steel stranded cable.
I always get mine at the bicycle repairshop. Make sure you get the galvanized type, not the stainless steel!
For bushing the bellcranck and horns I recommend brass, not copper (too soft, wears out)
Did I mention bellcrank size?
Anyway, we went bigger and bigger, because of the extra movement your lines will be making.
That way, you'll be diminishing the influence of play, flex and whatever more non control inputs trying to influence your commands. Because of the larger moment arm, the differential forces required in the lines are less (remember, the maximum differential equals your line tension), yielding a more positive control through

Nowadays I'm flying with 100 mm (~ 4") between the lines at the bellcrank and a handle spacing of ~ 5 "
This is slowing down the controls as well, so giving you a much better command at subtle corrections.
My control ratio is somewhere near 1 :1 handle/elevator deflection.
When the response feels too sluggish, you can always open up your handle spacing.

I strongly recommend a tipweight trim box in the outer wing tip and adjustable lead out guides in the inner.
Lead out guides.jpg
tip met verst lead-outs.jpg
There is a world of difference between a properly trimmed model and one that is accurate to the plan but just that...


I put in another sabbattical from F2B, my batteries have come to the end of their life span and I can't find anything new that comes near in dimensions, weight and capacity. Effectively grounding my best F2B model.
I was flying 4S-3200mAh, 40C 275 grams, 135 x 42x 22 mm.
That's what I had and worked perfectly, but Revolectrix stopped making them.
Anything else sofar is missing capacity, doesn't fit or is too heavy or a combination of this.... :(

It's not all doom and gloom however, it gives me time to revive my Vintage RC projects and button only TX.
11.jpg
19.jpg
15.jpg
17.jpg
Op de grond 05-07-2015 4.jpg
Last edited by F2B on 16 Dec 2019, 17:46, edited 3 times in total.
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PaulJ
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Re: Thunderbolt

Post by PaulJ » 16 Dec 2019, 08:27

:o ..... I had never realised there was so much to a C/L model. It's a bit different to the KK Champ I built when I were a lad! :lol:

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F2B
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Re: Thunderbolt

Post by F2B » 16 Dec 2019, 13:58

PaulJ wrote:
16 Dec 2019, 08:27
:o ..... I had never realised there was so much to a C/L model. It's a bit different to the KK Champ I built when I were a lad! :lol:
It's also different from the CL trainer I made in 1966. :lol:
So are the differences between a Howard Bonner 'Smog Hog' and a current F3A model. :o
All we do is adjust, try, modify and try again. :roll:
Decades later you find yourself with a totally different model.... ;)
F2B or not to be....

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